Database Manual / Reference / Query Language / Query Predicates / Comparison

$gt (expression operator)

Definition

$gt

$gt selects those documents where the value of the specified field is greater than (i.e. >) the specified value.

For most data types, comparison operators only perform comparisons on fields where the BSON type matches the query value's type. MongoDB supports limited cross-BSON comparison through Type Bracketing.

Compatibility

You can use $gt for deployments hosted in the following environments:

  • MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud

Syntax

The $gt operator has the following form:

{ field: { $gt: value } }

Examples

The following examples use the inventory collection. Create the collection:

db.inventory.insertMany( [
   {
      item: "nuts", quantity: 30,
      carrier: { name: "Shipit", fee: 3 }
   },
   {
      item: "bolts", quantity: 50,
      carrier: { name: "Shipit", fee: 4 }
   },
   {
      item: "washers", quantity: 10,
      carrier: { name: "Shipit", fee: 1 }
   }
] )

Match Document Fields

Select all documents in the inventory collection where quantity is greater than 20:

db.inventory.find( { quantity: { $gt: 20 } } )

Example output:

{
  _id: ObjectId("61ba25cbfe687fce2f042414"),
  item: 'nuts',
  quantity: 30,
  carrier: { name: 'Shipit', fee: 3 }
},
{
  _id: ObjectId("61ba25cbfe687fce2f042415"),
  item: 'bolts',
  quantity: 50,
  carrier: { name: 'Shipit', fee: 4 }
}

Perform an Update Based on Embedded Document Fields

The following example sets the price field based on a $gt comparison against a field in an embedded document.

db.inventory.updateOne(
   { "carrier.fee": { $gt: 2 } }, { $set: { "price": 9.99 } }
)

Example output:

{
  _id: ObjectId("61ba3ec9fe687fce2f042417"),
  item: 'nuts',
  quantity: 30,
  carrier: { name: 'Shipit', fee: 3 },
  price: 9.99
},
{
  _id: ObjectId("61ba3ec9fe687fce2f042418"),
  item: 'bolts',
  quantity: 50,
  carrier: { name: 'Shipit', fee: 4 }
},
{
  _id: ObjectId("61ba3ec9fe687fce2f042419"),
  item: 'washers',
  quantity: 10,
  carrier: { name: 'Shipit', fee: 1 }
}

This updateOne() operation searches for an embedded document, carrier, with a subfield named fee. It sets { price: 9.99 } in the first document it finds where fee has a value greater than 2.

To set the value of the price field in all documents where carrier.fee is greater than 2, use updateMany().

Tip